重点讲解：
1. vow to do sth. 发誓；起誓；立誓；
He vowed to take legal action.
他誓言要采取法律行动EA2R#@oH.Uq7HFWI4=QQ。
2. part of 一些；部分；
The change is part of the government's policy of phasing in Arabic as the official academic language.
这一变革是政府将逐步采用阿拉伯语作为官方学术语言政策的一部分JT9s_KBFLv13xS^f;tf。
3. at least （数量）至少，不少于；
He has killed many in his time, and is wanted in at least three countries.
他那个时候杀了很多人，现在至少有3个国家在通缉他Tlff,Yi+u)~-I(mAy。
4. at large 在逃的；未被捕获的；
He remains at large despite the high price put on his head by the authorities.
尽管当局悬赏重金缉拿他，他仍旧逍遥法外|10;4HQ(XNi_l]eB7c。